Preparation of biological samples, such as DNA, RNA, mRNA and protein from clinical samples in the forms of solids and fluids, may involve a series of processing steps, such as tissue dissociation, cell separation, cell lysis, gene extraction, and/or washing. This sometimes requires complex fluidic delivery and processing protocols. In some conventional processing methods, samples and reagents are contained and manually transferred using test tubes and micropipettes. This is time-consuming, labor-intensive, and prone to human error. There is also a significant risk of cross-contamination of nucleic acids between different samples. Some of the manual steps and operations may be automated using robotic systems, but the robotic systems are difficult to use for handling small amounts of samples. Moreover, automation typically requires added costs and expensive equipments.
A chip-based or cartridge-based micro-system can process a small amount of sample fluid within a closed fluidic system, thereby reducing risks of cross-contamination. Typically, the fluid flow within the chip- or cartridge-based systems is driven and regulated using pumps and valves. These systems have complex structures and low reliability, and are expensive and inconvenient to use.